As Facebook enters its second decade, it's time to take a look back at its first.

When Mark Zuckerberg and friends launched it, the website was "the facebook." An unidentified male watched your activity — most of which consisted of making minor updates — from the top-left corner of the page.

Early adopters will recognize the mini-feed, lists of personal information, and blue bars that used to separate each part of the page. They'll remember when the news feed was born in 2006, or when the “like” button appeared in 2009. (There’s still no way to "dislike.") The profile page and news feed have evolved to include larger photos, more messaging options, and advertisements. Facebook's user-base has grown to include much more than just the college students it originally targeted.

Take a look at that evolution in the above screenshots, starting with a group page from 2004. The design was boxier back then, with blue headings for each section. Facebook reached 1 million users in December 2004.

The profile picture permanently moved to the top-left corner in 2005. This version of the profile page emphasized users' personal information, with lists of favorite music, TV shows, movies, and quotes appearing alongside political views, contact information, and interests.

Here we see an expanded version of the mini-feed, which offered updates on a user's most recent Facebook activity. That type of information was compiled in a news feed homepage launched in September 2006. Facebook for mobile also launched that year, while the website opened up registration for anyone.

The numerous "My" options in the left rail have been replaced by a cleaner menu with icons. Privacy and account settings moved to the top-right corner, where they remain today. The mystery Facebook-man has disappeared from the top-left corner.

The profile of this era emphasized to the user status, while restricting them to "is" statements. For example, "Amy Weller is excited about the new redesign." Basic information became clickable. Recent activity floated to the top. Facebook pages and self-service ads launched that year.

This page feels familiar, with the "wall" serving the function of a late mini-feed or early timeline. Tabs made it easy to navigate to info and photos. This version of the profile page gave users three different fields to express a status, which could be confusing.

A summary of the user's information appeared at the top of this profile page. Recent photos were below. (Some of my more creative friends used those five photos to create one larger photo.) Tabs disappeared.

The news feed's left rail got longer and more icon-dominated, looking even more like it does today. Facebook chat took on a new look. Facebook opened its first custom-built data center in January 2010 and reached 500 million users in June.

"The Social Network," starring Jesse Eisenberg as Zuckerberg, was released in 2010. The film received positive reviews and eight Oscar nominations, but was criticized by some for its dramatization of Facebook's early days. It depicted the contemptuous relationship Zuckerberg had with the Winklevoss twins, who have taken credit for the website's idea.

This is not quite the news feed of today, but you'd be forgiven for confusing the two. Birthday and life events popped out more with profile pictures. 2012 was a big year for the company, which went public the same week Zuckerberg got married. Facebook acquired Instagram in April 2012 and reached 1 billion users in October.

This is the news feed of tomorrow -- or some other point in the future. Parts of it look similar to today's with birthdays, events, and trending appearing in the right rail. The left rail combines icons and Facebook chat for the first time since 2011. The style of the center stream looks different, with larger photos.

Now that Facebook is 10 years old, the world's largest social network faces a paradox of sorts: The company must somehow forge a new identity for a future always in flux.

On one hand, Facebook has successfully personalized the Internet for one-seventh of the world's population while becoming a $7-billion-a-year pillar of Wall Street.

Yet its heavy reliance on potentially cyclical advertising revenues and the constant threat from newer attention-grabbing competitors such as Snapchat poses serious obstacles for the Menlo Park, Calif., company. Even Facebook's dominance in social networking is tenuous, given the soaring popularity of Google Circles.

“Maybe you can say most of the first 10 years were about establishing themselves as the leader in what they're doing to connect people,” said analyst Brian Blau, research director at Gartner. “But can they monetize what people do and what people say in a way that's not creepy and provides real value for businesses?”

Experts say the social network's chances rest on CEO Mark Zuckerberg's well-documented “move fast and break things” philosophy, even if it means a few failures along the way.

“One of Mark's greatest strengths is that when he sees change happening, he embraces it rather than trying to avoid it,” former Chief Technical Officer Bret Taylor said. “So for me, I believe it will exist in 10 years for that reason. But I don't know what it will be in 10 years.”

For his part, Zuckerberg urges patience as the company looks for new ways to generate revenue from its popularity.

“There's no real business plan that supports the billions of dollars of investment that we're going to make in trying to bring connectivity to the rest of the world,” he said at a recent computing conference. “But we're doing it because we think it is the right thing to do and I think that tends to have a way of catching up in a positive way over time ... It's one of the tricky things about capitalism, you can't connect all the dots ahead of time.”

Since co-founding Facebook in his Harvard dorm room on Feb. 4, 2004, Zuckerberg has constantly pushed to change the social network's look and functionality.

Some initiatives failed miserably, such as Facebook Beacon, a widely derided attempt to get Facebook members to share what they were buying, and Poke, a largely ignored mobile app that was supposed to compete with the popular ephemeral photo-sharing app Snapchat. But photo sharing did propel Facebook to popularity, as did the News Feed.

“I'm not sure if Facebook has figured out what their future is,” Blau said. “I think we'll see more experiments, more failures and more successes. In two or three years from now, we'll probably see from them what their future will look like.”

That experimentation continued this week with the U.S. launch of a stand-alone iOS app called Paper, Facebook's attempt at creating a personalized newspaper for smartphones and tablets.

Paper is the first product from Facebook Creative Labs, small teams of employees who are trying to innovate Facebook's future. Zuckerberg said in a recent earnings call there are several new mobile products in the pipeline for this year, part of three-year and five-year strategic plans that are “all about building a new kind of experience for sharing.”

Former Facebook CTO Taylor, who in 2010 helped launch the “Like” button that spread Facebook's influence to all corners of the Web, said the social network became a “cultural phenomenon” by making the Internet seem more personal by offering an alternative to impersonal websites and computerized search services such as Google.

Today, Facebook has 1.23 billion monthly active users, including 945 million monthly active users who log in through a mobile device. Net income for 2013 rose to $1.5 billion on revenues of $7.87 billon.

But getting to the next billion members alone may not be enough for Facebook to thrive.

Blau believes Facebook is at a “crossroads” because it needs to diversify its revenue streams to support future growth. In the fourth quarter of 2013, $2.34 billion of Facebook's total revenue of $2.59 billion came from ads.

One avenue could be figuring out what to do with information Facebook's data scientists are gleaning from studying millions of day-to-day interactions across the platform. That cognizant computing, as Blau calls it, could be valuable for e-commerce companies.

“What they'll have in five to 10 years is a treasure trove of data showing how people change over time,” Blau said. “And when you can start to predict their behavior, that's going to be very powerful.”

Yet the greatest threat to Facebook could come from a startup or a technology that no one can envision today.

Taylor points to the game-changing launch of the iPhone in 2007.

“It's more likely that someone's creating something completely different than Facebook that happens to impact Facebook,” he said. “That's the weird thing about technology. No one could really describe the iPhone until they started using an iPhone.”